Vacuum steam heating system



` l Fb. 4,1930. H. M. wYLlE. ET AL 1,745,822

) y VACUUM STEAM HEATING SYSTEM Filed Jan. 4, 1928 Qur Patented eb. 4, 1930 UNITED STATESv PATENT OFI-'Ica HOWARD M. WYIQIE ANDy HAROLD E. ADAMS, OF SOUTH NORWALK, CONNECTICUT, ASSIGNORS TO NASH ENGINEERING COMPANX'OII;` SOUTH NORWALK, CONNECTI- CUT,v A CORPORATION OF CONNECTICUT vAcUUM ASTEAM HEATING SYSTEM Application led January 4, 1928. Serial No. 244,513.

This invention relates to heating systems of the low pressure or vacuum type in which pumps are provided for removing air from the system and for returning the Water of condensation to the boiler.V

It is one object of our linvention to provide improved connectionsfin such a system,

f n by which the return flow of the condensate is yof portions of a vacuum steam heating system, and v Fig. 2 is a perspective view of a slight mod- 'ificatiom Referring to Fig. 1,'vve have shown a low l pressure or vacuum steam heating system comprising a boiler 10, a supply plpe 11, a

radiator or other heat radiating apparatus 12, and a return pipe 13. The radiator 12 f is connected by an inlet pipe 14 to the supply pipe 11 and is connectedthrough a steam trap 15 and discharge pipe 1G to the return pipe 13. lIt will be understood that the heat ing system commonly comprises a large number of radiators 12 or other radiating apparatus, all of which, however, are connected between the supply pipe 11 and return pipe 13V substantially as indicated. 40 v The condensate from the radiators flows down through the return pipe 13 to a separating tank 20. to which suitable pumping apparatus 21 is connected. The pumping apparatus preferably comprises an airpump for withdrawing air from the tank 20 and y discharging the same through a separator 22 to a vent pipe 23. and a centrifugal'water pump adapted to Withdraw the water or con-- v densate from the tank 20 and to deliver the same through a discharge pipe 25 tothe boiler 10. The apparatus thus far described is of the usual commercial type and in itself forms no part of our presentinvention.

An undesirable condition sometimes arises in vacuum or low pressure heating systems of the type above described, if the fires are too tightly banked under the boiler or if the system is for any other reason permitted to cool down to too great an extent. Under these conditions, a vacuum may be formed on the supply side of the system, suiiicient to prevent ovv of condensate from ythe radiators 12 through the return pipe 13 to the tank 20.

To oii'set this condition, it has been proposed to provide a by-pass or equalizing connection, as the pipe 30, between the supply pipe 11 and some point on the return side of the system` such as the top of the tank 20. A checkvalve 31 in the pipe 30 opens toward the supply pipe 11 and prevents the' flow of vapor or steam in the opposite direction toward the return pipe 13, whenever the pressure in the supply pipe 11 exceeds the pressure in the return pipe 13, which is the normal operating condition. One feature of our invention Aconsists in providing a branch connection 32 from an intermediate point in the equalizing pipe 30 to an elevated point in the return pipe 13, and in providing a check valve 33 in the pipe 30 between the tank 2Q and the branch pipe 32, said check valve opening away from the tank 20. y

The object' of the branch connection 32 is to permit the iow of air or vapor from the tank 20 to an elevated point in the return pipe'13 at the same time that the water of condensation Hows down in the pipe 13 to the tank 20.k This avoids the necessity of the air finding its way upward through the same pipe in which the water is descending, and greatly improves the circulation in the lower part of the pipe 13, accomplishing a more rapid and uniform flow of the condensate to the separating tank 20.

lVe have also provided a by-pass connection 4() from the lower end ofthe return pipe 13 to the discharge-pipe 25 beyond the pumping apparatus 21. A check valve 41 is ply of electric power or for some other reason,

but it is essential that the return of condensate to the boiler shall continue without substantial interruption. By the use of the connections above described,.a head of water may be built up in the return pipe 13 suiiicient to overcome the dierence'in pressure between the return pipe and the boiler and toreturn the condensate to the boiler, by-passing the same around the stalled pumping apparatus.

As previously stated, the vent pipe 23er(- tends to a height corresponding to a head greater than is necessary for returning the condensate, so that no water willleave the system by overflow from the vent pipe while building up a pressure in theV return pipe 1n excess of the boiler pressure.

Insome cases it may not be desirable to eX- tend the vent pipe to so great a height, and in such'cases we may substitute the construction shown in Fig. 2, in which' the vent pipe 23 is connected to a chamber 44having an open discharge pipe 45 and aY valve 46 controlled by a iioat 47. Under normal conditions, the chamber 44 contains little water,

the valve 46 is open, and the entire structure' acts as an ordinary ventV pipe. If, however, the head of water built up in the return pipe ycauses water to rise through the vent pipe 23 to the chamber 44, the float 47 will close the valvel 46 and prevent over-flow of water through the discharge pipe 45. V l

From this description, it will be seen that we have facilitated the return ofthe water of condensation to the separating tank 20 and that we have provided'for automatically bypassing the condensate around the pumping apparatus, if disabled, both of these matters being of great importance in the operation of a vacuum heating system.

Having thus described our invention and the advantages thereof, we donot wish to be limited to the details herein disclosed otherwise than as set forth in the claims, but what we do claim is 1. In a vacuum steam heating system, av

boiler, a circulation system including a supply pipe, radiating apparatus, a return pipe, pumping apparatus effective to lremove air from the system and to return the water of condensation to the boiler, and an additional connection from said pumping apparatus to an elevated point in said return pipe, permitting up-iiowof air and vapor thereth'ough as the water of condensation flows downward in said return pipe to said pumping apparatus.

2. In a vacuum steam heating system, a boiler, a circulation system including a supply pipe, radiating apparatus, a. return pipe,

pumping apparatus eifective to remove air from the system and toy return lthe Water of condensation to thc boiler, an equalizing connection ybetween the supply and return sides of the system permitting flow of air and Vapor toward said supply pipe in the event of abnormally low pressure in said supply pipe, means to prevent reverse flow in said equalizing connection, and a branch connection from said equalizing connection to an elevated point in said return pipe, permitting up-ilow of air and vapor therethrough as the water of condensation ilows'downward in said return pipe to said pumping apparatus.

3. In a vacuum steam heating system, a

ply pipe, radiating apparatus, a4 return pipe,

boiler, acirculation system including a suppumping apparatus effective to remove air from theV system and to return the water of condensation to the boiler, an equalizing connection between the supply and return sides of the system permitting How of air and vapor toward said supply pipe in the event of abnormally low pressure in said supply pipe, ai branch connection from said equalizing connection to an elevatedpoint in said return pipe, permitting vup-low of air and vapor 'therethrough' as the water of'condensation flows downward in said return pipe to said pumping apparatus, and means to prevent reverse flow through said branch connection and. through said equalizing connection.

In testimony'whereof we have hereunto affixed our signatures.

HOWARD M. WYLIE. HAROLD E. ADAMS.v 

